In the case of copyright it means that your claim to be the author of a particular work cannot be challenged by, say, a copyright infringer.

Use the post

There have been, over the years, all sorts of ways of ensuring non-repudiation and protecting copyright. One of our favourite examples is that of, say, a musician who composes a work, puts the score in an envelope and the posts it to themselves. When the envelope arrives in the post, it contains a postmark (i.e. the date it was posted). The artist then stores the envelope away, unopened.

If ever a dispute arises as to the copyright of the work, the musician can produce the envelope and demonstrate (beyond repudiation!) that they had the work at least from the date on the postmark.

Shaky ground?

Of course, the validity of such a non-repudiation method can always be disputed. An infringer could claim, for example, that the envelope was steamed open at a later date and a different score substituted.

So the non-repudiation claim is only as strong, ultimately, as the strength of the relationship between the given work (the score) and the proof of ownership of that work at a given point in time (the postmark).

Enter the immutable blocks

This is what makes Nottario’s blockchain service so powerful. You take your work and instead of posting it inside an envelope addressed to yourself, you “post” it to the Ethereum blockchain inside a smart contract. For that contract to be validated it gets added to a block. Every block in the blockchain has a date stamp. Hey presto, your work and the date stamp have been bonded forever!

Because of the unique characteristics of a blockchain, it is basically impossible to tamper with any of the contents of a block without it being noticed, including its date stamp. So you have a bulletproof statement that binds your work to a point in time. A statement that cannot be repudiated.

No-show

And there is more: to use Nottario to protect your copyright, you don’t even have to post your work to the blockchain, only a unique digital fingerprint of it. As long as you have your document stored safely, only that document will have that unique fingerprint. So you are not even revealing anything about your music, design or invention when you use Nottario to create a notarisation certificate.